Generally the conditioning of a room is carried out letting an air current into it with continuity and removing an equal quantity thereof. This is the principle of the conditioning by convection.
However, the comfort of the man in a room derives, at least to a large measure, from the transfer of heat or energy by radiation. The heat transfer by radiation is caused by the giving up of heat of a warm surface to a colder surface. By regulating the transfer of radiant heat and the air temperature by convection, one can achieve an unsurpassable degree of comfort.
Thereby conditioning systems have been developed based on radiation instead of convection. Through radiation one can carry out both the heating and the cooling of a room. The radiation is carried out through radiant panels with electric conductors or pipes for air or water. By "radiant panels" panels are meant in the art that carry out a heat transfer at least for 50% under radiant form.
However the radiant panels presently known are floor or ceiling panels, and the percentage of heat transferred by radiation and not by convection is not high and in any case to operate efficiently they need considerable temperature difference between the panels and the room, which involves energy expenses.